Loud-speaking apparatus



Oct. 1'5, 1929. F. w. cooLEY LOUD SFEAKING APPARATUS Filed Dec.. 6. 1926 I/v vE/v To/f. I H750 W CMLEX (157 ///5 /777'0//VEY5. iff# Patented Oct. l5, 19.29

PATENT OFFICE FRED W. COOLEY, OF MINNEAPOLIS, MINNESOTA LOUD-SPEAKING APPARATUS Application led December 6, 1926. Serial No. 152,827.

This invention relates to a loud speaking device, or a tone modifying device for a sound transmitting or a sound reproducing machine, and while the device is capable of many applications, one particular use in which it has been found to have great utility is that in modern radio receiving sets. Such receiving sets usually comprise .a casing having a panel at the front thereof, the various parts of the apparatus being disposed in said casing. It is desirable that any loud speaking device or tone modifying device used in a radio set be so constructed as to be durable and to consistently maintain a high quality of tone.

The present invention is an improvement upon that disclosed and claimed in applicants Patent 1,603,069, granted October 12, 1926. In said patent and in the present invention, a pair of tubes are used of elastic material, arranged in co-axial and telescoping relation, said tubes being held in rigid relative position and being connected by a suitable securing means. With the spacing means previously used, it has been found that after some time the material would become compacted and the portion thereof in contact with the tubes would adhere or stick thereto. This would obj ectionably affect the vibration of the tubes and would dampen the tone thereof so as to make it lose its desirable quality. g

It is an object of this invention, therefore, to provide a tone modifying device comprising a pair of tubes of elastic material having spacing and securing means therefor which will be very durable and which will consistently maintain a high quality of tone.

It is also an object of the invention to provide a spacing means for the tubes of rigid material, which will notk naturally adhere to the tubes and which will not become objectionably compressed from-msc.

It is still another object of the invention to provide a securing and spacing/means for the tubes comprising a yielding ,material and la layer of material vadjacent th tubes which is comparatively hard and will l ot adhere to the tubes. 4

It is also an object of the invention to provide a connecting and securing means for the tubes including a layer of sand paper.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings, in which like reference characters refer to similar parts throughout the several views and in which Fig. 1 is a view for the most part in vertical section through a portion of the apparatus, showing the tubes used and the securing and spacing means therefor; and

Fig. 2 is a vertical section taken on line 2 2 of F ig. l, as indicated by the arrows.

Referring to the drawings, an apparatus is shown comprising a base or supporting member 5 which may be the bottom of a radio cabinet. A front piece or panel 6 is secured to and upstands in vertical position from the member 5, which member 6 may form part of the front panel of the radio receiving set or the front panel of the loud speaking apparatus. A casing 7 is secured to the rear side of member 6 and while this casing may be of various shapes, in the embodiment of the invention it is illustrated as of cylindrical shape. The casing 7 has secured therein adj acent its rear end a tube 8. The tube 8 is made of elastic or vibrant material, and while various materials might beused, well seasoned hard wood has been found to be very eflicient in practice. It will be noted that the tube 8 is spaced from the inner wall of the casing 7 throughout the greater portion of its length, said tube having circumferentially spaced and longitudinally extending recessed portions or ribs 8 which contact with the casing 7 so as to hold said tube firmly in position. A block 9 is disposed adjacent the rear end of casing 7, having a recess in its outer side receiving one end of the telephone receiver l() such as now commonly used in radio work, said receiver having the usual conductors 1()a extending therefrom. A washer 11 of hard rubber or similar material is disposed between the face of the receiver 10 and the block 9 and said block is centrally bored co-aXiall, with the tube 8 to receive the central projection 1 0'nl of the receiver 10 which extends through the opening in block 9 and engages a washer 12 of hard rubber or of wood. A diaphragm 13 of hard elastic material such as metal or mica is disposed some distance in front of the Washer 12 and has at each side thereof gaskets or Washers 111, the opening in the latter being substantially the same as the opening in tube 8 While the opening in diaphragm 18 Vis substantially the same as that in the receiver proj ection 10a and in the Washer 12. The. central portion of the diaphragm 18 is also separated from the Washer 12 by a smaller Washer 15 having the opening therein substantially the same as the opening in the diaphragm 13.

The parts 12 and 14 are held against the end ofthe tube 7 by the block 9, which in turn is clamped to the panel 6 by suitable means such as the headed and nutted bolts 16 extending in spaced relation between said block 9 and panel 6. A smaller tube 17 made of material similar to the tube 8 is disposed in tube 8 and coaxial therewith, having its inner end spaced slightly inward from the end of the tube 8 and having-its outer end projecting slightly beyond the end of the tube 8. The tubes 17 and 8 are spaced by a member 18 disposed adjacent the outer end of the tubes and extending for a short distance longitudinally and circumferentially thereof. As shown in Fig. 2, one side of the member 18 tapers toward the tube 17 and the other side tapers toward the tube 8. The member 18 is made of some rigid and fairly' elastic material and While various materials might be used, in practice said member has been found to be veryeiiicient made of seasoned Wood. as shown in Fig. 2, the member 18 has a groove 182i` extending longitudinally thereof, which groove extends throughout the length of said member adjacent its edge which is tapered toward tube 17, having its open side directed toward said tube, and said member has another groove 18b extending longitudinally thereof adjacent the edge which is tapered toward tube 8, said groove having its open side directed towards said tube 8. A suitable adhesive such as glue secures the Ymember 18 to the tubes 8 and 17 respectively outside of the grooves 18a and 18D.- rlrhere is thus no glue throughout the greater portion of the area of the member 18 which contacts the tubes 8 and 17, the glue extending only from the grooves 18a and 18b to the edges adjacent the same. A pair of spacedl headed and nutted bolts 19 extendjthrough tubes 17 and 8`and through the member 18, being alined in the direction of an element of said tubes and having Washers 2O of leather or similar material beneath the heads and nuts thereof. A layer 21 of some compressible or yielding material such as composition rubber, and a layer 23 of felt are disposed between the Washers 2O and the surfaces of the tubes 8 and 17 respectively, and a layer 22 of some comparatively hardand non-adhesive material such as sand paper is disposed between the layers 21 and the sur- Also,

faces of the tubes 8 and 17. A layer 24; of Wood is placed 1oetween layers 23 and 20 at the head ends of bolts 19. The nuts on bolts 19' are tightened so that the tubes are brought into close contact with. member 18 and are held in fixed relative positions. lt Will be noted that the casing 7 is cut aivav at 7 a, forming an opening in which the layers 21 and 22 under the heads of bolts 19 are disposed.

In operation the telephone receiver 10 is operated in the usual Way and the sound Wavesgenerated thereby pass through the ktubes 8 and 17. The tubes are set into vibration and the sound Waves are so modified and affected that a loud, distinct and pleasing tone issues from the front of the tubes. T he spacing member 18 is not attached or connected to the tubes through the greater portion of its area and thus does not stick to the tubes and objectionably affect their vibration andthe tone produced. r1`he member being made of rigid material also does not become greatly compressed in use'. rihe tubes are held in corr ct alinoment and the layers of sand paper 22 also prevent the yielding material 21 and 28 from becoming connected or stuck to the tubes. 1t has been found in practice that it is this sticking of the materialto the tubes that dampens the vibration and objectionably affects the tone. ,At the same time, the yielding material is desirable under the Washers 20 in order that cracks orcreakings will not occur in the operation of the device Which would be greatly amplified. These yielding members contribute Ato the softness and pleas-` ing quality of the-tone. Y

From the above description uit is seen that applicant has provided a simple,eliicient and improved structure of loud speaker or tone modifying device. The device has been given a long test and its efficiency and utility amply demonstrated in actual practice. r1`he same has been found vto Vbe very successful and er'iicient.v

' 1t Will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts, Without departing from the scope of applicants invention, which, generally stated, consists in a device capable of carrying out the objects abovesset forth, in the novel parts and combinations of parts disclosed and delined in the appended claims.

"What is claimed is 1 A tone-modifying Ydevice for a sound reproducing machine. comprising a pair of co-axially arranged telescoping tubes of elastic material'bothhaving openings atboth ends, means securingsaid tubes in xed relative positions, 14anda spacingmeans of rigid material betvve n said tubesv extending an appreciable di tance circumferentially thereof, having a large part of its area incontact with,VK but unatjtach'ed to, said' tubes and a smaller portion of its area attached to said tube.

2. A tone modifying device for a sound reproducing machine, comprising a pair of coaxially arranged telescoping tubes of elastic material both having openings at both ends thereof, means securing said tubes in fixed relative positions, and a spacing means of rigid material between said tubes, said means being attached to said tubes at portions disposed at opposite sides thereof and adjacent its edges but having a comparatively large area inside of said portions in contact with the tubes unattached to said tubes.

3. A tone modifying device for a sound reproducing machine, comprising a pair of coaxially arranged telescoping tubes of elastic material, means securing said tubes in fixed relative positions, and a spacing member of wood between said tubes, said spacing member having portions at opposite sides adjacent its edges attached by adhesive respectively to said tubes but having a larger part of its area extending circumferentially between said portions contacting said tubes unattached.

4. A tone modifying device for a sound reproducing machine, comprising a pair of coaxially arranged telescoping tubes of elastic material, means securing said tubes in fixed relative positions, and a spacing means of rigid elastic material extending circumferentially around and between said tubes, said means being secured at opposite sides respectively to said tubes throughout narrow portions adjacent its longitudinal edges by adhesive, but having a larger portion of its area in contact with said tubes unattached thereto.

5. A tone modifying device for a sound reproducing machine comprising a pair of coaxially arranged telescoping tubes of elastic material, means securing said tubes in fixed relative positions, including a layer of sand paper in contact with one of said tubes.

6. A tone modifying device for a sound reproducing machine comprising a pair of coaxially arranged telescoping tubes of elastic material, a spacing member between said tubes, means securing said tubes in fixed relative positions comprising means at the inner side of one tube and at the outer side of the other, including layers of sand paper in contact with said tubes.

7 A tone modifying device for a sound reproducing machine, comprising a pair of coaxially arranged telescoping cylindrical tubes of elastic material open atboth ends, means securing said tubes in fixed relative positions, and a spacing member of wood between said tubes. l,

8. A tone modifying device for a sound reproducing machine comprisingia air of coaxially arranged telescoping cylin rical tubes of elastic material open at both ends, means securing said tubes in fixed relative positions,

and a spacing means of rigid elastic material between said tubes whereby said tubes will be held in permanent and fixed relative positions.

9. The structures set forth in claim 8, said first mentioned means comprising members extending through said tubes and spacing means and including yielding means at the sides of said tubes directly opposite said spacing means.

10. A tone modifying device for a sound reproducing machine comprising a pair of coaxially arranged telescoping tubes of elastic material, means securing said tubes in fixed relative positions, a spacing means of rigid material between said tubes having a large part of its area in Contact with, but not attached to, said tubes, and yielding means at the sides of said tubes directly opposite said spacing means but not adhering to said tubes.

l1. A tone modifying device for a sound reproducing machine comprising a pair of coaxially arranged telescoping tubes of elastic material, a spacing member between said tubes, and means securing said tubes in fixed relative position comprising a layer of sand paper in contact with one of said tubes.

In testimony whereof I aiiix my signature.

FRED W. COOLEY. 

